There exist various chemical and biological analysis techniques which employ radiation emitter tagging. One such technique is gel electrophoresis which produces a radiation tagged flat image having a multiplicity of lines on a gel, each line representing a molecular component of given characteristics.
Increasingly, for the purpose of research and clinical diagnostics it is desired to quantify the results obtained, such that computer analyses and operations can be applied thereto.
One existing technique is to contact print from the gel onto radiation sensitive film. This technique, known as autoradiography, is slow, due to the relatively low radiation intensity involved and can require days in order to obtain a useful result, which must then be digitized by the use of a densitometer.
There are also known apparatus and techniques for automated reading of tagged images, such as that exemplified in the Betascope 603 Blot Analyzer which is available from Betagen Corporation of 100 Beaver Street, Waltham MA 02154, U.S.A.
There is also known a radioanalytical imaging system which operates by scanning a sample with an ionization gas detector and provides resolution to at least 0.8 mm. Such a system is commercially available from AMBIS Systems of San Diego, Calif. 92123, U.S.A.
The AMBIS system employs a collimator which totally blocks all radiation from certain regions on the sample. Accordingly, in order that valuable and important information not be lost, the AMBIS system requires that the location of the sample be shifted repeatedly with respect to the collimator.
Automatic techniques for analysis of non-radioactive electrophoretic gels are also known. Apparatus and software employing such a technique is available from Pharmacia LKB Biotechnology AB, of Uppsala, Sweden under the trademarks UltroScan XL and GelScan XL.
Various types of multi-step radiation detectors are known in the detection art. Examples of papers in this area include the following:
The Multistep Avalanche Chamber for Beta Radiochromatography by Ariella Cattai, Nuclear Instruments and Methods in Physics Research 215 (1983) pp 489-492;
The Multistep Avalanche Chamber as a Detector in Radiochromatography Imaging, by G. Petersen et al, Nuclear Instruments and Methods 176 (1980) pp 239-244;
An Improved Multistep Avalanche Detector System for Digital Autoradiography, by J. E. Bateman, et al, Nuclear Instruments and Methods in Physics Research A264 (1988) pp 430-435;
The Multistep Avalanche Chamber, A New Family of Fast High Rate Particle Detectors, by A. Breskin et al, Nuclear Instruments and Methods 161 (1979), pp 19-34; and
A multistep parallax-free X-ray Imaging Counter, A. Breskin, et al., Nuclear Instruments and Methods 195 (1982) pp 469-473.
A systematic study of the emission of light from electron avalanches in low pressure TEA and TMAE gas mixtures by D. Sauvage, A. Breskin and R. Chechik Nuclear Instruments and Methods A275, (1989) pp 351-363;
On the Optical Readout of Gas Avalanche Chambers and its Applications, by M. Suzuki, A. Breskin et al., Nuclear Instruments and Methods in Physics Research A263 (1988) pp 237-242;
Some Applications of the Imaging Proportional Chamber by G. Charpak, A. Breskin, R. Chechik et al, presented at the IEEE Nuclear Science Symposium, San Francisco, 21-23 October 1987, IEEE Transactions on Nuclear Science, NS-35, p 483 (1988);